1. 1. The sale transaction reported on this Form 4 was effected as a part of an underwritten public offering of common stock by Karyopharm Therapeutics Inc. with the Reporting Person as a selling stockholder in the offering.

2. 1. The sale transaction reported on this Form 4 was effected as a part of an underwritten public offering of common stock by Karyopharm Therapeutics Inc. with the spouse of the Reporting Person as a selling stockholder in the offering.

/s/ Christopher B. Primiano as Attorney-in-Fact for Sharon Shacham

07/02/2014

** Signature of Reporting Person

Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person,
see
Instruction
4
(b)(v).